On 05/29/2014 02:26 AM, Arnd Bergmann wrote: > On Wednesday 28 May 2014 14:41:52 H. Peter Anvin wrote: >> On 05/19/2014 05:36 AM, Arnd Bergmann wrote: >>> >>> My feeling is that all devices we can think of fall into at least one >>> of these categories: >>> >>> * legacy PC stuff that needs only byte access >>> * PCI devices that can be accessed through sysfs >>> * devices on x86 that can be accessed using iopl >>> >> >> I don't believe PCI I/O space devices can be accessed through sysfs, but >> perhaps I'm wrong? (mmapping I/O space is not portable.) > > The interface is there, both a read/write and mmap on the resource > bin_attribute. But it seems you're right, neither of them is implemented > on all architectures. > > Only powerpc, microblaze, alpha, sparc and xtensa allow users to mmap > I/O space, even though a lot of others could. The read-write interface > is only defined for alpha, ia64, microblaze and powerpc. > And how is that read/write interface defined? Does it have the same silly handling of data sizes? -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
